Fixed-Site Water Quality Monitoring Network: Time Series Data throughout Narragansett Bay By Heather Stoffel URI/GSO October 2, 2006

What is Time-Series Data? Continuous water quality monitoring of the physical conditions Continuous water quality monitoring of the physical conditions Parameters: temp, salinity, DO, pH, CHL, and turbidity Parameters: temp, salinity, DO, pH, CHL, and turbidity Other Supporting Data: weather, tidal & flow data Other Supporting Data: weather, tidal & flow data

Why is it important to Coastal Managers? Help to clarify goals – –Help to define the extent of the hypoxia issue Describe trends – –Baseline data Analyzing conditions – –Provides information for water quality reports Inventing, evaluating, and selecting alternatives – –Monitoring program

Data Collection TemperatureSalinity Dissolved Oxygen pHChlorophyllTurbidity YSI 6600 EDS

Narragansett Bay Fixed-Site Water Quality Monitoring Network Agencies: RIDEM-OWR, URI/GSO, NBNERR, NBC, NBNEP, & RWU Site Locations: West Passage, East Passage, Providence River, Seekonk River, West Greenwich Bay, & Mt. Hope Bay Monitoring Season: buoy stations (May-Oct) & land-based stations (year round) Funding: NOAA Bay Window Program, EPA Clean Water Act (sections 319 & 106), & NOAA National Estuary Program

How Data is Distributed to Coastal Managers, Scientists, & Public BART (RIDEM-OWR)-weekly public posting of bay conditions BART (RIDEM-OWR)-weekly public posting of bay conditions Critical Stations: Bullock Reach, Conimicut Point, North Prudence, & Greenwich Bay Marina URI/GSO-daily observations URI/GSO-daily observations NBC-instantaneous readings NBC-instantaneous readings NBNERR-support national SWMP NBNERR-support national SWMP RWU-downloadable data RWU-downloadable data NBNEP-additional surveys & graphics NBNEP-additional surveys & graphics

Dissolved Oxygen Criteria For Surface Waters & Waters without a Pycnocline Waters with a DO concentration above an instantaneous value of 4.8 mg/l shall be considered protective of Aquatic Life Uses. Greenwich Bay Marina Station: Surface DO in 2003

Dissolved Oxygen Criteria For Waters with a Pycnocline (Bottom Waters) Waters with a DO concentration above an instantaneous value of 4.8 mg/l shall be considered protective of Aquatic Life Uses. When instantaneous DO values fall below 4.8 mg/l, the waters shall not be: 1. Less than 2.9 mg/l for more than 24 consecutive hours during the recruitment season; nor 2. Less than 1.4 mg/l for more than 1 hour more than twice during the recruitment season; nor 3. Shall they exceed the cumulative DO exposure presented in Table 3.A.

Allowable Number of Days without Exceeding a 5% Reduction in Seasonal Larval Recruitment

Bullock Reach Bottom Oxygen Levels:

North Prudence Bottom Oxygen Levels:

Mount View Bottom Oxygen Levels:

Hypoxia Event: August 15-25, 2003

Hypoxia Event : June 30-July 14, 2006

Total Number of Days Below DO Criteria of 4.8 mg/L at the North Prudence Station * = Incomplete Dataset Note: Critical Recruitment Season is May 1-October 31 * *

Total Number of Days Below DO Criteria of 2.9 mg/L at the North Prudence Station * = Incomplete Dataset Note: Critical Recruitment Season is May 1-October 31 * *

Hypoxic Event Summary /1-7/23 (10) 8/13-9/1 (19) 1.18 mg/L 0.68 mg/L NP/BR S B /28-7/10 (7) 7/29-8/8 (11) 1.4 mg/L 1.7 mg/L NP/BR S B /20-8/31 (72) (8/14-8/25) 0 mg/L BR,CT,NP, GB S B /19-7/25 (6) 8/14-8/20 (6) 1.92 mg/L 1.06 mg/L GB S B /30-7/5 (6) 7/30-8/18 (20) 3.5 mg/L 2.0 mg/L NP,MV,GB,CT,BR S B /29-8/10 (43) (7/30-8/10) 0 mg/L BR,CT,NP,MV,GB,QP,PP S B YEARDURATION DO MIN. SITE TEMP R

Hypoxia Trivia for Narragansett Bay 1.Hypoxia Season: June 12-September 28 2.Minimum Hypoxia Surface Temperature: 18.5 C 3.Minimum Hypoxia Bottom temperature: 15 C 4.River Flows were above the 10 year average: 2001, 2003, & 2006